ATI TEAS Science

Correct Answer: A

Rationale: The correct answer is A because in a primary immune response, the first event is the recognition and phagocytosis of pathogens by macrophages. This is crucial for initiating the immune response by presenting antigens to T cells. Neutrophils (choice B) are important in later stages as part of the innate immune response. B lymphocytes (choice C) produce antibodies later in the response. Helper T cells (choice D) are activated by the antigens presented by macrophages and play a role in coordinating the immune response but are not the first event.

Correct Answer: A

Rationale: The correct answer is A: They're both accurate and precise. Rationale: 1. Accuracy: The measurements are close to the accepted value of 9.8 m/s^2, with a range of 9.78-9.81 m/s^2. 2. Precision: The measurements are consistent and clustered closely around the true value, indicating precision. 3. The slight variations in measurements are expected due to experimental error but still fall within an acceptable range. In summary, the measurements are accurate as they are close to the true value, and they are precise as they are clustered closely together. Other choices are incorrect because they do not accurately reflect the situation based on the provided data.

Correct Answer: A

Rationale: The correct answer is A: A plasma membrane. Both prokaryotes and eukaryotes have a plasma membrane as their outer boundary. The plasma membrane is essential for maintaining cell integrity, controlling the passage of molecules in and out of the cell, and facilitating communication with the external environment. Prokaryotes lack a nucleus enclosed by a membrane (choice B), which is a defining feature of eukaryotic cells. Eukaryotes have organelles (choice C) that are membrane-bound structures, unlike prokaryotes that lack membrane-bound organelles. A nucleoid (choice D) is a region in prokaryotic cells where the genetic material is located, but it is not enclosed by a membrane like the nucleus in eukaryotic cells.

Correct Answer: B

Rationale: To find the molarity, we first need to calculate the moles of NaCl. Moles = mass / molar mass = 4.0g / (23.0g/mol + 35.5g/mol) = 0.056 moles. Next, we convert the volume to liters (120mL = 0.120L). Finally, molarity = moles / volume = 0.056 moles / 0.120L = 0.57 M (Choice B). Incorrect choices: A: 0.34 M - Incorrect calculation of moles or volume. C: 0.034 M - Incorrect calculation of moles or volume. D: 0.057 M - Incorrect conversion of volume to liters.

Correct Answer: C

Rationale: The correct answer is C: Retina. Visual processing begins in the retina because it contains specialized cells called photoreceptors (rods and cones) that convert light into electrical signals. These signals are then transmitted through the optic nerve to the brain for further processing. The cornea (A) is the transparent outer layer of the eye that helps focus light, the optic nerve (B) transmits signals from the retina to the brain, and the eyelid (D) is a protective covering for the eye and does not play a role in visual processing.